Another paramedic said the region's 140-strong workforce felt let down by the union's response to the proposal to enlist firefighters and emergency service volunteers to respond to medical emergencies.

"There is no support from the Ambulance Service to provide appropriate services to the Illawarra," he said.

"We will not support it - let the fire brigade do everything. If that's what they want, that's what they'll get.

"We are so short-staffed ... wait until flu season, and bed block. We can't get crews to jobs now."

The First Responders Program is already operating in 48 locations in NSW, including Bundanoon in the Southern Highlands.

The Ambulance Service of NSW revealed details of existing Community First Responder arrangements after the HSU warned its members could strike if the program was rolled out to city areas.

The Illawarra crews said the service had little choice in country areas - where crews could be forced to drive more than 60 minutes to a job.

"But in city areas, it's wrong," the paramedic said.

"We are all gutted, absolutely gutted - there is no morale in the Illawarra, no nothing."

The HSU was contacted for comment on the issue yesterday.

The Mercury also sought response from the Ambulance Service.

The Fire Brigade Employees Union said there was "nothing to be gained" from entering the debate "for the time being".

In a post on the union's online forum, an Illawarra firefighter said the union had repeatedly tried to contact the HSU over the First Responders Program, but to no avail.

"It is regrettable that some of the comments made by the HSU have been less than complimentary to firefighters," the post said.